Material: Soft ANNEALED copper clad steel grounding conductor ,minimum 10mils copper Per UL-467 grounding & bonding equipment. Size: 4 AWG 50 feet per coil,One additional copper cable extension split bolt connector is included. 4 AWG annealed solid copper ground wire with steel core for greater tensile strength , great grounding conductor for industrial and residential lightning protection and DIY usages. The Soft ANNEALED wire can bear winding,bending and easy to straighten,with great conductivity ,corrosion resistance specially designed for grounding conductor and DIY usages. Perfect application and cost-effective.